Recent digital still cameras and digital video cameras normally have a facial detection function, and have a function of optimally matching various parameters (focus, brightness and the like) of the camera according to facial position and area.
In addition, Patent Literature 1 discloses a technique in which a user designates and selects a “main subject” that is a target subject to be tracked in a captured image.
In addition, if the techniques disclosed in Patent Literatures 2, 3, and 4 described above are used, for example, subject tracking that encompasses a frame of the whole body of an arbitrary subject can be realized.
In addition, there are also functions of controlling an optical system and the like such as autofocus and automatic exposure such that a desired area in a captured image is detected and traced so as to optimize the area.
As described above, technologies of tracking an image designated by a user as a main subject, for example, an image area such as a face in a captured image, focusing on the face area, and the like are known.